Decay of residual stress at indentation cracks during slow crack growth in soda-lime glass
- Royal Inst. of Tech., Stockholm (Sweden)
A recently developed method for measuring residual stresses was used to determine the decay of the residual stress field around 45-N Vickers indentations in soda-lime glass, during aging in moist air. Iso-stress contours were determined and compared with similar ones for virgin indentations of the same load. The residual stress field was found to decay significantly but not uniformly as environmentally assisted slow crack growth took place. In the region close to the crack tip a 32% decay in residual tensile stress was detected. A similar decrease in the residual stress parameter {chi}{sub r}, results in a value of the fatigue limit K{sub 0} = 0.42 MPa m{sup 1/2}. This value is in good agreement with literature fatigue limit values for corresponding relative humidities. From these observations, it was concluded that the often-observed strength increase of aged cracks, compared to virgin cracks, is likely to be due to stress release during slow crack growth.
- OSTI ID:
- 201070
- Journal Information:
- Acta Materialia, Journal Name: Acta Materialia Journal Issue: 2 Vol. 44; ISSN XZ504Y; ISSN 1359-6454
- Country of Publication:
- United States
- Language:
- English
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